Estimating is NOT like guessing!

Estimating is something TOTALLY different from guessing!
It is NOT "smart" guessing, or "educated" guessing

Guessing	Estimating
totally depends on luck	depends on thinking
cross your fingers	make sense
you CANNOT learn how to get luckier	you CAN learn to get better at this skill
use good luck	use facts that you know
no facts are needed	must have facts
no thinking is needed	must think
getting close is worthless	getting close counts as correct
a guess is either exactly right, or it is totally wrong	estimating between two numbers could be valuable
a guess must use all the correct place values	an estimate could still be useful with some place values left at zero